Aqueous Cutting Fluid for Use with a Diamond Wiresaw

Abstract

Water-based cutting fluids for use with diamond wiresaws that are used for cutting or otherwise treating hard brittle materials, e.g., silicon ingots, comprise: A. Water-soluble, polymeric dispersing agent, typically a polycarboxylate; B. Optionally wetting agent; C. Optionally defoamer; B. Optionally corrosion inhibitor; E. Optionally chelant; F. Optionally biocide; and G. Water. Typically water comprises at least 50 weight percent of the fluid, and the polycarboxylate is grafted with a polyalkylene glycol, e.g., polyethylene glycol.

1 . A cutting fluid comprising in weight percent based on the weight of the cutting fluid, at least:
 A. 0.05% of a water-soluble, polymeric dispersing agent comprising one or more groups that are negatively charged upon dissociation in water;   B. Optionally 0.01% wetting agent;   C. Optionally 0.01% defoamer;   D. Optionally 0.01% corrosion inhibitor;   E. Optionally 0.01% chelant;   F. Optionally 0.01% biocide; and   G. 50% water.   
     
     
         2 . The cutting fluid of  claim 1  comprising:
 A. 0.05-5% polycarboxylate dispersing agent; 
 B. 0.01-3% wetting agent; 
 C. 0.01-2% defoamer; 
 D, 0.01-2% corrosion inhibitor; 
 E. 0.01-2% chelant; 
 F. 0.01-1% biocide; and 
 G. 80% water. 
 
     
     
         3 . The cutting fluid of  claim 2  in which the
 A. polycarboxylate dispersing agent is PAG-g-polycarboxylate and the polycarboxylate of the PAG-g-polycarboxylate comprises units derived from acrylic acid; 
 B. Wetting agent is a secondary alcohol alkoxylate; 
 C. Defoamer is an organo-modified polysiloxane or polyether; 
 D. Corrosion inhibitor is at least one of an alkanolamine, borate ester, amine dicarboxylate or triazole; 
 E. Chelant is at least one of ethylenediamine N′N′-tetraacetic acid (EDTA) and its salts and derivatives; hydroxyethyliminodiacetic acid (HEIDA and its salts and derivatives; methyl-glycine-diatetic acid (MGDA) and its salts and derivatives; or glutamic-N,N-diatetic acid (GLDA) and its salts and derivatives; and 
 F. Biocide is at least one of triazine, oxazolidine, sodium omadine or iodocarbamate. 
 
     
     
         4 . A process of cutting a hard, brittle material with a wiresaw used in conjunction with a water-based cutting fluid, the process comprising the step of contacting the material with the wiresaw and cutting fluid under cutting conditions, the cutting fluid comprising:
 A. 0.05% of a water-soluble, polymeric dispersing agent comprising one or more groups that are negatively charged upon dissociation in water;   B. Optionally 0.01% wetting agent;   C. Optionally 0.01% defoamer;   D. Optionally 0.01% corrosion inhibitor;   E. Optionally 0.01% chelant;   F. Optionally 0.01% biocide; and   G. 50% water.   
     
     
         5 . The process of  claim 4  in which the cutting fluid comprises:
 A. 0.05-5% polycarboxylate dispersing agent; 
 B. 0.01-3% wetting agent; 
 C. 0.01-2% defoamer; 
 D. 0.01-2% corrosion inhibitor; 
 E, 0.01-2% chelant; 
 F. 0.01-1% biocide; and 
 G. 80% water. 
 
     
     
         6 . The process of  claim 5  in which the cutting fluid comprises
 A. PAG-g-polycarboxylate and the polycarboxylate of the PAG-g-polycarboxylate comprises units derived from acrylic acid; 
 B, Wetting agent is a secondary alcohol alkoxylate; 
 C. Defoamer is an organo-modified polysiloxane or polyether; 
 D Corrosion inhibitor is at least one of an alkanolamine, borate ester, amine dicarboxylate or triazole; 
 E. Chelant is at least one of ethylenediamine N′N′-tetraacetic acid (EDTA) and its salts and derivatives; hydroxyethyliminodiacetic acid (HEIDA and its salts and derivatives; methyl-glycine-diacetic acid (MGDA) and its salts and derivatives; or glutamic-N,N-diacetie acid (GLDA) and its salts and derivatives; and 
 F. Biocide is at least one of triazine, oxazolidine, sodium omadine or iodocarbamate. 
 
     
     
         7 . The process of  claim 6  in which the hard brittle material consists of silicon, GaAs or GaP. 
     
     
         8 . The process of  claim 7  in which the wiresaw is a diamond wiresaw. 
     
     
         9 . A cutting fluid concentrate comprising:
 A. PAG-g-polycarboxylate dispersing agent;   B. Optionally wetting agent;   C. Optionally defoamer;   D. Optionally corrosion inhibitor;   E. Optionally chelant; and   F. Optionally biocide.   
     
     
         10 . The cutting fluid concentrate of  claim 9  in which the wetting agent, defoamer, corrosion inhibitor, chelant and biocide are present, and the:
 A. PAG of the PAG-g-polyoarboxylate is PEG and the polycarboxylate of the PAG-g-polycarboxylate comprises units derived from acrylic acid; 
 B. Wetting agent is a secondary alcohol alkoxylate; 
 C. Defoamer is an organo-modified polysiloxane or polyether; 
 D Corrosion inhibitor is at least one of an alkanolamine, borate ester, amine dicarhoxylate or triazole; 
 E. Chelant is at least one of ethylenediamine N′N′-tetraacetic acid (EDTA) and its salts and derivatives; hydroxyethyliminodiacetic acid (HEIDA and its salts and derivatives; methyl-glycine-diacetic acid (MGDA) and its salts and derivatives; or glutamic-N,N-diacetic acid (GLDA) and its salts and derivatives; and 
 F. Biocide is at least one of triazine, oxazolidine, sodium omadine or iodocarbamate.